ARM: 7559/1: smp: switch away from the idmap before updating init_mm.mm_count

[deliverable/linux.git] / arch / arm / kernel / smp.c

diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 8e20754dd31d5946f5297aae2023ae2c8d5cd572..fbc8b2623d82f08c8c2926375a7b8a31f943361b 100644 (file)
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -294,18 +294,24 @@ static void percpu_timer_setup(void);
 asmlinkage void __cpuinit secondary_start_kernel(void)
 {
        struct mm_struct *mm = &init_mm;
-       unsigned int cpu = smp_processor_id();
+       unsigned int cpu;
+
+       /*
+        * The identity mapping is uncached (strongly ordered), so
+        * switch away from it before attempting any exclusive accesses.
+        */
+       cpu_switch_mm(mm->pgd, mm);
+       enter_lazy_tlb(mm, current);
+       local_flush_tlb_all();
 
        /*
         * All kernel threads share the same mm context; grab a
         * reference and switch to it.
         */
+       cpu = smp_processor_id();
        atomic_inc(&mm->mm_count);
        current->active_mm = mm;
        cpumask_set_cpu(cpu, mm_cpumask(mm));
-       cpu_switch_mm(mm->pgd, mm);
-       enter_lazy_tlb(mm, current);
-       local_flush_tlb_all();
 
        printk("CPU%u: Booted secondary processor\n", cpu);